Furnace top charging equipment



FURNACE TOP CHARGING EQUIPMENT Filed Jan. 5, 1966 2 Sheets-Sheet l INVENTORS 721/0 7'su rsww x/au/ Fl/Pl/ Y4 ATTORNEYS y 1968 TERUO TSUTSUMI ETAL 3,384,361

FURNACE TOP CHARGING EQUIPMENT Filed Jan. 5, 1966 2 Sheets-Sheet 2 T12. 2.. Tic En.

INVENTORS Tam/a Tsursmw 5404/ Fz/m/ YA ATTORNEYS United States Patent FURNACE TGP CHARGING EQUIPMENT T eruo Tsutsumi, Yokohama-shi, and Shoji Furuya, Tokyoto, Japan, assignors to lshikawajima-Harima Jukogyo K ushiki Kaisha, Tokyo-to, Japan, a Japanese company Filed Jan. 3, H66, Ser. No. 518,123 Claims priority, appliaation Japan, Jan. '7, 1965 3 Claims. (Cl. 266-27) ABSTRACT OF THE DISCLOSURE The bell of a bell hopper at the furnace-top opening is suspended and controlled by rods extending through said bell hopper, aside from the central top inlet of the latter. A stationary seal valve hopper with a swingable seal valve is disposed at this central top inlet to direct charging material upon the center area of said bell. To provide uniform fiow, skip cars or conveyor means pour charging material into said seal valve hopper at greater speed than that at which material flows off the open seal valve.

The charging equipment having the structure as shown in FIGJ is the most popularly adopted for metal refining furnaces, especially blast furnaces.

FIG. 1 illustrates the structural outline of the conventional furnace top charging equipment.

In these furnaces, the skip cars g, being hoisted up to the top of the blast furnace, are turned over at the top and pour the materials into the small bell hopper c through the stationary hopper f. The charging materials 1' thus poured into the small bell hopper 0 forms a pile pushed to one side. Accordingly, charging the materials as it is f into the furnace a will bring about serious troubles in the operation of the furnace such as ventilation to be caused by deflection of gas. To prevent such troubles, a driving device It rotates the small bell hopper c and the small bell e with the materials thrown in and is stopped at a certain position so as to distribute the materials uniformly along the circumference having its center on the center line of the furnace. Usually a large bell hopper b and large bell d are attached under the small bell e. Thus when the materials are being poured in, the small bell e is opened while the large bell d is closed and the large bell d is opened while the small belle is closed so as to prevent the inner gas from escaping into the atmosphere.

However, the equipment of this type has the following disadvantages:

(i) For the rotation of the small bell e and the small bell hopper c intended for the uniform distribution of the materials in the furnace a, a grease seal device i is equipped between the rotary part and the stationary part so as to prevent leakage of gas. However, with a popular adoption of the high pressure operation, the pressure of the gas within the furnace has increased correspondingly, making it difficult for the grease seal device i to guarantee the air-tight condition. So we are now in need of an airtight device of new structure.

(ii) In order to prevent the leakage of gas, a grease seal device i is installed, which, however, it accompanied with resistance to the rotation. Moreover, the small bell e and the small bell hopper c are made to rotate while a large quantity of materials are placed thereon. Thus a large amount of electric power is consumed.

(iii) The highest part of the pile of the materials charged into the small bell hopper c is brought to any one of the points appointed in advance, for instance the six points of 0, 60, 240, or 300 by means of the rotation of the small bell hopper 0 within a certain period of time, and at that point the small bell e is opened to fall the materials 1 onto the large bell d. But this kind of operation requires a limit switch that identifies and confirms the rotation angle, as well as the brake device that operates when the rotation reaches a predetermined point and control devices that causes the rotation of the small bell hopper and the opening and closing of the bells in a predetermined order. These devices involve high costs as well as complicated structures.

(iv) The bells, which are installed at the passage of the charging materials, have two functions of distributing the materials and preventing the leakage of gas inside the furnace. However, the small bell e, whose diameter is much smaller than that of the large bell d, is subject to violent abrasion on the surface caused by the flow of materials, and it will soon lose its function of preventing the leakage of gas from the furnace. Therefore, it becomes necessary to stop operation of the furnace for the replacement of the small bell e or to keep operation under the lowered pressure of gas inside the furnace, with the result that the efficiency of the furnace as well as the effectiveness of operation itself may be deteriorated.

The present invention relates to the furnace top equipment, whose purposes are to solve the foregoing problem of gas leakage caused by the rotation of the small bell and the small bell hopper and to be durable and moreover of low costs, characterized in that a furnace top seal valve and a distributor such as a hell are installed on the center line of the furnace at its charging part of the metal refining furnace so that the raw materials may be charged not to have an unequal distribution at said furnace top charging parts.

An embodiment of this invention will be explained reference to drawings.

FIG. 2 illustrates the structural outline of the furnace top charging equipment with the skip cars adopting the present invention.

FIG. 3 shows a section along line A-A of FIG. 2.

FIG. 3 shows a cross section B-B shown in FIG. 2.

FIG. 5 illustrates the structural outline of the furnace top charging equipment with a belt conveyor system.

In the drawings 1 refers to the inside of the furnace, 2 to a large bell hopper installed inside the furnace, 3 to a large bell, 4 to a stationary hopper, 5 to a furnace top seal valve installed on the center line of the furnace, 6 to a gas seal, 7 to an auxiliary distributor, 8 to bell rods, 9 to skip cars, It to a belt conveyor, 11 to a chute, 12 to the hopper for receiving materials, 13 to the gate at the furnace top, and 14 to the charging materials.

The stationary hopper 4 of bisymmetrical form is attached to receive the materials at the position where the skip 9 fully loaded with materials is overturned, and an air-tight furnace top seal valve 5, that fully opens immediately before the fall of materials and completely closes after all thematerials finish falling, is attached on the center line of the furnace under the said stationary hopper 4. In this way an airtight container is constructed of the large bell 3, the larger bell hopper 2 and the gas seal 6. As the occasion demands, a stationary distributor 7 is attached inside the stationary hopper 4 fixed above the with furnace top seal valve 5 or above the large bell 3 installed under the furnace top seal 5 in order to help to distribute uniformly the materials inside the furnace. Furthermore, the attachment of the furnace top seal valve 5 on the center line of the furnace has brought about the structure in which the large hell 3 is hung by plural rods 8 which deviate from the center line of the furnace at the bottom of the furnace top seal valve 5, whereas the large bell 3 has been hung on the center line by a single rod in the conventional method.

Here is the explanation of this equipment along the flow of the materials. The materials hoisted up to the furnace top by the skip car (a) fall into the stationary hopper 4, and then poured into the large bell hopper 2 through the furnace top seal valve 5 which is in the fully opened state. In this process, the materials are throttled by the furnace top valve 5. Thus the quantity of the materials going through the furnace top seal valve 5 is smaller than the original quantity which fall down from the skip car 9, and as a result the materials are poured into the large bell hopper 2, making a pile inside the stationary hopper 4. The majority of the materials pass through the furnace top seal valve 5 uniformly and are accordingly distributed in perfect uniformity inside the large bell hopper 2, while the minimal exception is that the foremost edge of the materials thrown form the skip 9 and the final portion thereof, both of extremely small quantity, are distributed in a biased way in the large bell hopper 2. This infinitesimal biased pile can be remedied by the attachment of a guide plate of a suitable shape or the attachment of a stationary distributor under the furnace top seal valve 5.

The furnace top seal valve 5 placed in the passage of the materials has its valve seat at a spot which prevents contact with the materials even during the passing thereof, and its body recedes to a position which is free from the efiect of the materials thrown in. After the materials have been completely poured into the large bell hopper 2, the furnace top seal valve 5 is closed and the large bell hopper 2 is shut out from the atmosphere. Only in this condition, the large hell 3 may be moved downwards to charge the furnace with the materials poured into the large bell hop per 2. Since the materials poured into the large bell hopper are already uniformly distributed along the circumference, the distribution inside the furnace 1 is improved more uniformly by large bell 3 to be perfect.

FIG. 5 represents an example adopting this invention for the furnace top charging equipment with belt conveyor 10. The explanation of the construction of FIG. 5 will be made in contrast with FIG. 2 wherein the skip car 9 is used. Whereas the skip cars 9 run on double tracks and therefore charge the materials at two different positions, making it necessary to attach a suitable guide plate for aiding distribution inside the stationary hopper 4, the belt conveyor 10 can charge the materials from one position against the center of the furnace, thus making it unnecessary to attach a guide plate for aiding distribution in the materials receiving hopper 12 installed under the chute 11. While the materials can be poured into the stationary hopper 4 at a time, in case the skip cars are used, the belt conveyor 10 charges the materials bit by bit and accordingly takes a considerably long time for this operation. Deferring from the skip 9 as mentioned above, the materials charged by the belt conveyor .10, after passing the chute 11, are once sotred in the materials receiving hopper 12 with a furnace top gate 13 below, and are poured into the large bell hopper 2 by means of the Opening of the furnace top seal valve 5 and the subsequent opening of the furnace top gate 13. The furnace top gate 13 installed under the materials receiving hopper 12 is used for storing and releasing the materials and need no airtight structure. The reason why the charging equipment of belt conveyor system is supplied with the materials receiving hopper 12 and the furnace top gate 13 in particular is that the materials take longer time in falling from the belt conveyor than from the skip and therefore the furnace top seal valve 5 is kept open for a longer time in case the materials are thrown into the large bell hopper 2 through the furnace top seal valve 5. During this period of time, the gas in the furnace 1, being air-tight in the large bell 3, is not to be released to the atmosphere, but the structure of the large bell 3 is so made as to make it inevitable for the materials to contact the seat area while being poured in. Therefore, we cannot reasonably expect the perfect airtight condition to continue for a long time and there is gas leakage to some degree. Therefore to keep the furnace top seal valve 5 close longer is better. So installing the furnace top gate 13 opens and closes interlocked with the furnace top seal valve 5, we can keep the furnace top seal valve 5 open for the same duration of time that the materials are charge by the skip 9.

As for the uniform distribution of the materials which is the main purpose of this invention, the belt conveyor system is especially effective since it can charge all the materials in the direction of the center of the furnace.

The characteristic effects of the charging equipment of this invention are as follows:

(I) The charging materials can be uniformly distributed in the furnace, without restorting to the installation of any rotary mechanism, on the basis of the attachment of the furnace top seal valve on the center line of the furnace instead of the small bell, and of the attachment of the stationary hopper above the furnace top seal valve and on the basis of a suitable regulation of the flow of the charging materials going through the furnace top seal valve by means of the fixing of a disturbing plate inside the said hopper as occasion demands.

(11) Since the rotary mechanism has been dispensed with, the grease seal device is not necessary. Hence there is no worry about possible leakage of gas at the grease sealed parts.

(111) Since the rotary mechanism has been dispensed with, we need no reduction gear, no driving device, and no control device for causing the rotary movement. Hence a considerable saving in the cost of equipment can be achieved.

(IV) Since time for rotation is not required, the time thus saved can be used for increasing number of charge. Hence a large quantity of materials can be charged at a higher speed.

(V) Since the furnace top seal valve, the seat of which does not directly touch the materials and the valve disk of which can shun the passage for materials, is installed for a small bell, the sealing area is free from abrasion to be caused by the charging materials. Hence the airtight condition can be maintained for a long time.

(VI) Since the furnace top seal valve mentioned above is smaller than the small bell and can be replaced with a new one from outside, it can be replaced easily for a short time if the air-tight condition should be damaged. The replacement of only the seat portion of the furnace top seal valve can bring the whole equipment back into a workable condition. Hence this is very economical in comparison with the conventional method of discarding the entire small bell.

(VII) Since the furnace top seal valve is of a small size and is not subjected to the load of the charging materials at the time of opening and closing operation, for less motive power is necessary for the opening and closing operation as well as for such mechanism itself than in the case of the conventional small bell.

What We claim is:

1. A furnace top charging device comprising: a bell hopper arranged in a gas-tight manner at the furnace top opening and having a conically shaped bell suspended for axial movement by a plurality of rods extending through said bell hopper aside from the top inlet thereof, said bell being adapted to prevent gas leakage in its closed position and, to evenly distribute about its circumference charging materials from the bell hopper into the furnace in its open position, a stationary seal valve hopper arranged in a gas-tight manner at the bell hopper top inlet and being provided at its bottom outlet with a swingable seal valve which, in its closed position, prevents gas leakage and, in its open position, is retracted to permit free passage of charging materials upon the center area of said bell without contact of said materials against said seal valve; and charging material feed means operatively disposed above said seal valve hopper and adapted to pour out a larger amount of said material then that passing through said open seal valve.

2. The charging device according to claim 1 wherein said material feed means, includes a pair of skip cars adapted to be hoisted above said stationary seal valve hopper.

3. The charging device according to claim 1 wherein 15 6 said material feed means comprises a storage hopper arranged above said seal valve hopper, said storage hopper having a swingable gate, and a conveyor means provided with a chute centrally arranged above said storage hopper to store charging material therein.

References Cited UNITED STATES PATENTS 5/1910 Hixon 26631 X 4/1954 Tesch et a1 214--36 

